现用山核桃的甲（AABB）、乙（aabb）两品种作亲本杂交得F₁，F₁测交结果如下表，下列有关选项不正确的是（　　）

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    Hello. I'm Peter. I'm a pupil. I go to school and study the boring knowledge(知识) every day now. I hope our school will change in the future. Schools will be different then. They will be under the sea, on high mountains and even in space. Robots will help us find books in the library and do our homework at home. We will use computers in all our lessons. They will help us see dinosaurs and other interesting things. We will have lessons with students from other countries. We will do a lot of things online together. We won't carry books to school. All our books will be on a small computer.

    We think that life in Chinese high school is an adventure in which we have to survive mountains of homework and all kinds of exams. Yet would it be____(surprise) if I tell you that high school life in the US is almost as stressful and demanding as it is in China?

    In US high school, everything____(record) into your studying document, including your grades on quizzes, tests and final examinations. Failing____(turn) in your homework on time will directly affect your grade for a certain course. Perhaps contrary to____we used to think of the US high school students, they pay more attention to their____(academy) performance to try to get into a distinguished university.____, they'll be disappointed after graduation from high school.

    Like university students, US high school students have the____(free) to choose the courses that most interest____(they). Even a ninth grader can sit____the same classroom as twelfth graders. But this also means he or she has to work very hard, because the teacher will not treat him or her differently just because he or she is a few years____(young).